Modern armored vehicles have been, of late, increasingly equipped with platen-like, plate-like, or lamella-like armored walls, referred to hereinafter as layered armor, which form so-called multiple targets and structured targets against which earlier even high-velocity subcaliber projectiles have a limited penetration. Such vehicles can also have so-called "active" armor which contains an interference charge which is triggered upon impact to shield the vehicle from the projectile, dislocate the latter or otherwise reduce or prevent penetration.
It has been proposed heretofore to attack such active armor and so-called multiple targets and structured targets by impact projectiles which pierce the multi-layer ablative armor by progressively breaking through the layers.
The term "impact projectile" is thus used to refer to a projectile which pierces the armor mainly, if not exclusively, as a result of its kinetic energy and mass, only a limited portion of the penetration at best being a result of any armor-breaking warhead which may explode upon contact with the armor. In fact, in most impact projectiles of the aforedescribed type, no explosion occurs upon contact of the projectile with the armor.
Reference may be had to the inertial or impact projectile described in the commonly assigned copending application Ser. No. 949,067 of Sept. 5, 1978 now abandoned and replaced by Ser. No. 412,794 of Aug. 23, 1982, this projectile having a plurality of cores or elements of hard metal which successively penetrate the layers of multiple and structured targets and active armor of the aforedescribed type.
Apart from the inertial or impact projectiles of the aforedescribed type, the art is aware of systems in which a main element of a projectile is provided with an auxiliary element which is substantially similar to the main element although the latter is much larger than the auxiliary element and the auxiliary element is caused to be effective against the target before the effective point of the main element. In short, in such weapons, the auxiliary element serves to initiate penetration of the target and improve the efficiency of the penetration of the main element.
A projectile in accordance with the principles described above is the subject of French Pat. No. 2,310,547.
The main device is, in this case, a so-called hollow or shaped charge with a conical liner or insert whose diameter corresponds to the inner diameter of the casing or sheath. At an axial spacing ahead of this main device, in the firing direction or direction of flight toward the target, is provided an auxiliary device with a hollow or shaped charge of reduced diameter. The latter, upon striking an active armor on a target vehicle, explodes and facilitates penetration of the main charge and its spike-forming insert.
Thus the prior-art arrangement described above has so-called tandem hollow charges which, experience has shown, undergo undesirable energy scattering or dissipation in directions other than the impact or armor-breaking direction.
Such scattering may result in frequently unavoidable deviations from symmetry of the spike-forming insert or from the relationship of the tandem charges to one another, i.e. deviations from exact axial alignment, or from the effect of the interference charges of active armor.
Furthermore, the explosions of the two charges directly follow one another from a time point of view and there is an unavoidable reaction on the part of the smaller initially exploded charge against the energy released by the larger hollow charge in spite of the fact that the charges are effective in the same region of the target.
For this purpose, a standoff must be provided for the smaller or initially exploded hollow charge which may result in non-overlapping effects of the penetration of the two charges.